Carrier Acqua Junior 30AJ Series Installation, Operation And Maintenance Manual page 57

5.3 Cold water piping/connections
Develop a piping design in a way it has minimum changes
of the elevation levels. Install manual or automatic air
purge valves at the highest points of the line, keeping the
system pressure through a pressurization tank with relief
and reducing valves. Install thermometers and pressure
gauges at the water outlet and inlet lines of the unit.
Install measurement points of the fl ow at the cold water
piping. To adjust as table, characteristics techniques, the
loss of nominal load of the evaporator.
It is recommended to use a globe valve to set the
water flow. Put draining connections at all the low
points of the hydraulic installation in order to allow a full
draining of the system. Install blocking valves near the
water inlet and outlet connections. To clean the lines
before the operating units use fl exible connections at
the chiller piping in order to reduce the transmission
of vibrations.
5.4 Filters
ATTENTION
It is advisable to use mesh fi lters installed in the
evaporator inlet liquid line (Plate Exchanger), the
nearest possible to the inlet piping.
5.5 Electric connections
a) General power supply:
Install near the unit a switch isolator with fuses or a
thermomagnetic circuit breaker with equivalent rupture
characteristics. The technical data of the unit are indicated
on table 5.6.
Consult an electric engineer or an accredited technician to
evaluate the electric system conditions and the proper
protection. Carrier is not liable for problems caused by the
non-observance of this recommendation.
It is recommended to use a lock to block the switch or any
open circuit breaker during the maintenance of the unit.
b) Power cabling:
Install the connection from the power input point of the
customer directly to the terminal of the unit.
The power supply cables should bear the sum of the
maximum currents. Do not forget to install the protective
cable (grounding). The voltage shall be in accordance to
the voltage of the nameplate.
The section of the feeder from the unit must more be
dimensioned for addition of maximum chains, or either,
equal the 125% of compressor or motor greater 100% of
all the other compressors and engines. The handles will
have to be classe 90°C or superior.
The voltage between the phases shall be balanced within
the 2% of imbalance and the current within 10%, with the
compressor in operation. Contact your local power supplier
in order to correct any improper voltage or the
phase imbalance.
Voltage imbalance calculation:
- Voltage imbalance (%)
Max. deviation of the average voltage x 100
=
Voltage average
- Exemple:
383 + 378 + 374
- Voltage average =
- Maximum deviation of the voltage average:
AB = 383 - 378 = 5
BC = 378 - 378 = 0
AC = 378 - 374 = 4
-Highest difference is 5V. Then, the voltage imbalance in
% is:
5 x 100 = 1,32%
378
Obs:
The following items can cause voltage imbalance:
• Bad contact (in contact with contactors, electric
connections, loose cables, oxidized or burnt conductors);
• Improper conductor sections;
• Load unbalancing in 3-phase power supply system.
- The current imbalance calculation shall be made in the
same way as the voltage imbalance calculation.
c) Cold water fl ow switch (cwfs)
On each unit there must be a cold water fl ow switch in
order to protect the equipment against low water fl ow
(Not provided/ installer responsibility).
IMPORTANT
If a water fl ow switch is not installed, the equipment
warranty will be void.
The installation must be made in the water
outlet installation.
ATTENTION
It is necessary to have care in the installation of
the key of the fl ow cold water. The indicative arrow
marked in the lateral of the water fl ow will have
to be pointed in the direction to the fl are in the
exit nipple.
To great details it goes until the electrical diagram and
verifi es the interconnection of the key fl ow with
the quipment.
380V - 3Ø - 60Hz
- Measurement:AB = 383 V
BC = 378 V
AC = 374 V
= 378V
3
(OK)
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